I don't see anything in the ui for deleting player profiles. I tried blowing out the BG3 documents folder, and that didn't do the trick, in fact it recreated everything.
So it must be cached somewhere, but I didn't see any kind of cache dir or anything like that in the BG3 steam directories. So I figure steam must be cacheing it or something? But even after blowing out everything again and giving the machine a restart in the hopes that would blow out whatever's cached, but it created everything again.
How do you remove profiles?
If your Profile was recreated, then thats somekind of Cloud Saving. You can swwtich it off in Steam Settings for every game, and probably under GoG too.
Deleting profile is working with the lil X, as @ulgrym wrote.